Best Ever Orange Sponge Cake

Note: If desired, spray tube pan or kugelhopf pan with nonstick baking
spray before filling with batter and baking. To cool, DO NOT invert on
bottle. Instead place pan on wire rack to cool 30 minutes. Turn cake out
onto wire rack and cool completely. In large bowl of electric mixer, let
egg whites warm to room temperature, about 1 hour. Measure flour; sift
about 2 cups flour once on a sheet of waxed paper; fill cups lightly to
overflowing; with a spatula, cut off excess to make 1 3/4 level cups. Sift
flour with salt; set aside. With electric mixer at medium speed, beat egg
whites until foamy. Gradually, beat in 1/2 cup of the granulated sugar, 2
tbsp at a time, beating well after each addition. Continue beating until
stiff peaks form when beaters are slowly raised. Preheat oven to 350
degrees. In small bowl of electric mixer, with the same beaters at high
speed, beat egg yolks until very thick and lemon colored, about 3 minutes.
DO NOT UNDER BEAT. Gradually, beat in remaining 1 cup granulated sugar;
continue beating until mixture is smooth. At low speed, blend flour mixture
and orange juice alternately into egg yolk mixture, beginning and ending
with flour and guiding batter into beaters with scraper. Add orange peel.
With whisk or rubber spatula, using under and over motion, fold yolk
mixture gently into whites. Pour batter into an ungreased (see note 1) 9
3/4 to 10″ x 4 1/2″ kugelhopf pan or 10 x 4″ tube pan without removable
bottom. Bake 50 to 55 minutes until cake springs back when pressed with
finger. Invert over bottle (see note 1); cool completely. Using an up and
down motion, run spatula around edge of cake and tube. Invert cake and
shake to release; place on serving plate. Sift Confectioners sugar over top
of cake. To cut cake, use knife with serrated edge. Cut gently, going back
and forth with sawing motion.